The invention discloses a sweet potato vermicelli processing method and a processing unit thereof, relating to a sweet potato deep-processing technology in the technical field of processing of agricultural products. The sweet potato vermicelli processing method disclosed by the invention comprises the following steps: 1, preparing raw materials; 2, pasting, namely (1), pasting acidic sweet potato starch; and (2), pasting alkali sweet potato starch; 3, stirring slurry, namely (1), stirring slurry of acidic sweet potato starch; and (2), stirring slurry of alkali sweet potato starch; 4, mixing slurry; 5, pumping slurry in vacuum; 6, curing preliminarily; 7, rapidly cooling and aging; 8, curing; 9, humidifying and aging; 10, blowing for aging; 11, drying; and 12, packaging. Sweet potato vermicelli prepared by the processing method disclosed by the invention is good in mouth feel, soft and flexible during eating; the production process is environment-friendly; furthermore, the sweet potato vermicelli is free from any food additive; and the sweet potato vermicelli processing method disclosed by the invention is not only capable of processing sweet potato vermicelli by using sweet potato starch as the raw material but also capable of processing vermicelli by using rice or other grains, such as millet, red rice, black rice, sorghum, oat, wheat germ, soybean, mung bean, red bean, petits pois, black soya bean, purple sweet potato, Chinese yam and potato, as the raw materials.